Flue arrangement



Jan. 30, 1962 F. BORK FLUE ARRANGEMENT Filed Aug. '7, 1959 United ttes Patent 3,019,000 FLUE ARRANGEMENT Frank Bork, 1460 W. Victoria, Chicago, Ill. Filed Aug. 7, 1959, Ser. No. 832,196 1 Claim. (Cl. 257-164) The invention relates to arrangements for handling gaseous products of combustion from a heating unit such as a boiler or furnace, and more particularly, to a flue arrangement which provides substantial elimination of smoke, gases and corrosion promoting particles from the combustion gases while also providing auxiliary heating.

It is the principal object of the invention to provide a novel flue arrangement for furnaces, which substantially eliminates smoke and noxious gases and increases the efiiciency of the furnace associated therewith. Other objects of the invention are the provision of a flue arrangement which can provide heat for the surrounding region, be economically installed and maintained, and which will provide reliable service over an extended period of time. Additional objects and advantages of the invention will be understood by reference to the following description, and to the accompanying drawings, in which:

FIGURE 1 is an elevational view, partly in section, of a flue arrangement which embodies various features of the invention;

FIGURE 2 is a sectional view taken along line 22 of FIGURE 1;

FIGURE 3 is an end view taken along line 3-3 of FIGURE 1; and

FIGURE 4 is a top view of the flue arrangement shown in FIGURE 1.

The advantages of the invention are obtained by locating the novel flue arrangement into which the spent combustion gases are discharged between a heating unit and a chimney venting the furnace to the atmosphere. Although advantages will be realized in connection with other types of heating units wherein gases are produced, the arrangement described herein is of particular advantage in connection with oil burners wherein the combustion products are particularly noxious and great in quantity. As shown particularly in FIGURE 1, numeral 11 represents the combustion chamber of a furnace and numeral 13 represents the inlet into a chimney. The flue arrangement therebetween comprises a first header or inlet 15 in communication with the combustion chamber 11, a second header or outlet 17 in communication with the chimney inlet 13, and a plurality of flue pipes 19 which connect the headers 15 and 17 and which are preferably disposed in parallel relation to one another.

The headers 15 and 17 are generally similar to one another and are fabricated from heavy sheet metal in generally rectangular form, although other shapes may be used and still obtain certain of the advantages of the invention. As shown, the header 15 includes one side wall 21a having a pattern of holes 23a for receiving the flue pipes 19. The opposed side wall 25a has a clean-out opening 27a and a cover plate 29a which is hinged along its top edge to the side wall 25a and is urged into engagement with the side wall over the opening 27a by a spring 31a. The header 17 also incorporates one side wall 21b having a pattern of holes 23b into which the flue pipes 19 are received and an opposed wall 25b including a clean-out opening 27b, and a cover plate 2% biased by a spring 31b into covering relation to the opening 27b. The size of the clean-out openings 29a and 29b is preferably generally coextensive with the area encompassed by the pattern of holes 23a and 23b to permit easy access to the flue pipes through the headers, thereby facilitating cleaning of the flue pipes.

The hot combustion gases pass from the combustion fr IC chamber '11 through a duct 33 to the inlet header 15 which is located above the combustion chamber. While the duct 33 may be joined to the header 15 on either of the other two side walls, in the disclosed construction, the duct enters the bottom wall 34a. The chimney inlet 13 through which the gases travel from the disclosed flue arrangement, is joined to the outlet header 17 along one of its side walls, although the chimney inlet could be connected to another part of the upper portion of the header.

As the duct 33 leading from the combustion chamber 11 enters through the bottom Wall 34a of the inlet header 15, it is preferred to clean the flue pipes by brushing the soot, and other material condensed therein, from right to left as seen in FIGURE 1, thereby collecting the deposited material in the outlet header 17. While such material may be removed from the outlet header through the opening 27, if desirable, the bottom wall 34b can be removable or can be provided with a detachable access to enable easier removal of the accumulated material.

The flue pipes 19 are economically constructed of relatively thin, sheet metal tubes 35 each having a relatively small diameter and long length. Each end of the tubes 35 is provided with a nipple 37 which is preferably force fitted therein and which is threaded at its free outer end. Thus, the flue pipes may be readily assembled and/or removed from the headers by means of a pair of bolts 39 arranged in the manner shown.

In order to achieve maximum removal of the soot and noxious material from the furnace exhaust, the tubes 35 are preferably of substantial length, thereby extending the period during which the gases are contained therein and providing increased opportunity for deposit of the soot and other suspended particles from the gases. In addition, the tubes are disposed horizontally to thereby avoid mass velocity of the gases in the upward direction and the consequent tendency to maintain the soot, etc. in suspension.

The headers and flue pipes will become heated during the passage of the hot combusion gases and will act as heat transmission surfaces for radiating and conducting heat to the surrounding environment in the basement or wherever else located. In this regard, the relatively thin walls of the tubes 35, as compared to the remainder of the flue arrangement, provide for greater heat transfer. Of even greater importance, it is to be noted that this exchange also produces cooling and condensation of the water vapor in the gases. This condensation and the accompanying precipitation result in entrapment of a large part of the suspended solid particles, thereby aiding in removal of these materials from the gases.

Consequently, the smoke and noxious fumes which would otherwise pass out the chimney to the atmosphere are reduced to collectable form within the flue arrangement and a virtually pure air stream passes through the outlet 17 to the chimney. The condensate, soot etc. thereby collected in the tubes can be readily removed by cleaning, and thus, collection at this point tends to prevent corrosive action elsewhere, thereby lengthening the useful life of the remainder of the system. Of course, the headers 15 and 17, the tubes 35 and nipples 37 are preferably treated to withstand corrosive action, as for instance, by galvanizing.

Still another important advantage of the disclosed flue arrangement is found in the more complete combustion which takes place in the combustion chamber. This desirable effect results from bafliing of the gases in the inlet header 15 incident to the right angle change in direction of gas flow and the separation of the gases into the several small streams during entry into the tubes 35. The bafflingor throttling action is effective to retain the products of combustion within the chamber 11 until more complete combustion has taken place.

One embodiment which has been eflective in obtaining the various features of the invention included eight flue pipes of .022 inch thick galvanized sheet metal having a length of about 10 feet and an outer diameter of about 2% inches. The nipples at each end of the sheet metal tubes were of galvanized steel, having a length of about 3 inches, having an outer diameter of about 2% inches, and were engaged in the tubes for a length of about 2 /2 inches. The headers were constructed of .038 inch thick galvanized sheet metal, having a height of approximately 16 inches and a square cross section of about 8 inches on each side. The flue pipe receiving side walls included a pattern of eight flue pipes receiving holes, as shown, which were arranged on 3 inch centers, having diameters of 2% inches. The diameters of the inlet duct 33 and chimney inlet 13 was 6 inches.

Although shown and described with respect to particular apparatus, various modifications may be made without departing from the principles of this invention.

I claim:

A flue arrangement for handling the natural flow of combustion products from a heating unit to the outside atmosphere, said flue arrangement comprising a plurality of generally straight, horizontally disposed elongated flue pipes disposed in relatively closely spaced-apart relation, a first header positioned at one end of said flue pipes in communication therewith, said first header comprising a box-like structure having connection through a vertical wall thereof with said pipes and including an opening in the bottom thereof aflording communication with a combustion chamber of a heating unit, a second header connected at the other end of said flue pipes in communication therewith, said second header comprising a box-like structure having connection through a vertical wall thereof with said pipes and including an opening at the upper portion thereof which has its axis generally at right. angles to the direction of said flue pipes for placing said header in communication with a chimney, whereby the combustion products enter said first header at the bottom thereof and then turn at a right angle to flow horizontally through said flue pipes and into said second header where the direction of flow is again changed by a right angle turn to flow outwardly through the chimney opening, said flue pipes being exposed along their lengths to the atmosphere surrounding the flue and having dimensions affording a throttling effect on the flow of the combustion products as the latter flow from said first header into said pipes, said pipes also being constructed and arranged to provide for a heat exchange with the surrounding atmosphere suflicient to cause condensation in said pipes of the moisture in the combustion gases, each of said headers having means defining an opening in a vertical wall thereof opposite said vertical wall having connection with said flue pipes, and a springbiased cover plate for the last mentioned opening in each of said headers, whereby access is provided to the flue pipes and whereby excessive pressure in said flue system is relieved through movement of said cover plates to a position away from their normal position covering the openings.

References Cited in the file of this patent UNITED STATES PATENTS 895,926 Wickham Aug. 11, 1908 1,530,809 Bowman Mar. 24, 1925 2,104,804 Hill Jan. 11, 1938 2,567,452 Strahan Sept. 11, 1951 

